Researchers from the University of Manchester developed a new way to modify the transmission of light that goes through a silicon wire (waveguide) - by wrapping graphene around the wire. Such silicon waveguide can be used to build a photonic microchip, and have also applications in highly sensitive bio-chemical sensor devices and perhaps photo detectors too.
The waveguides in this research are built in loops shaped like oval racetracks - and are called racetrack resonators. In a bio-chemical sensor, the light that leaks out of the waveguide is used for chemical sensing. The graphene coating adds further capabilities to such a sensor, such as making it more sensitive and selective. The researchers say that the graphene dramatically alters the way the light is guided through the device.